250-500 MC LOW-NOISE TRAVELING-WAVE TUBE AMPLIFIER
Abstract
Ten tubes were built and 6 of these were tested. Three items to further improve noise figure performance were incorporated. Thes are: (1) a 20% larger diameter cathode and beam, (2) an enlarged opening in the bucket collector, and (3) coating the inside of the collector with carbon. Gains obtained when potentials were optimized for best noise performance were of the order of 30 db + or - 1 db over the octave frequency band. Noise performance improved from previous tubes. Noise figures less than 4.6 db over the octave band were obtained and the best single frequency noise figure of 2.5 db at 328 Mc was obtained. Saturated power output in excess of 0.5 milliwatt was measured with an input signal strength of -27 dbm. Reverse attenuation was measured and found to exceed 75 db over the operating frequency band. Two tubes accrued running times in excess of 400 hours each with no sign of emission slumping or degradation of noise figure. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 14, 1961
- Accession Number
- AD0262204
Entities
People
- Robert E. Vehn
Organizations
- Watkins-Johnson Company